Sound translating device



y 1941- A. E V\VOODRUFF 2,241,106

SOUND TRANSLATING DEVICE Filed May 24, 1958 FIG.'I

so 4j 49 INVENTOR. F G ALBERT E. WOODRUFF /sm, m M M ATTORN E Y5 respect to the sets of adjacent Patented May 6, 1941 UNITED STATES PATENT "OFFICE 1 2,241,105 SOUND TRANSLATING onvron Albert E. Woodruif, Oak Park. 111., a'sslgnor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application May 24, 1938, Serial iv. 209,803

5 Claims. 01. 175-336) The present invention relates to sound translating devices and particularly to a winding spool and armature assembly for a sound trans-.- lating device of the magnetic or sound powered type. More particularly, the invention relates to an improved winding spool and armature assembly of the type of that disclosed and claimed in the copending application of Harold C. Pye, Serial No. 209,805, filed May 24, 1938.

In a telephone transmitter of this type, a magnetic field structure is provided which conventionally comprises a permanent magnet and two sets ofadjacent pole pieces, the adjacent pole pieces'of each set being of opposite polarity. A pivotally mounted magnetic armature is associated with the magnetic field structure, the

- opposite ends of the armature being disposed between the pole pieces of the respective sets. A sound wave responsive-diaphragm is connected and arranged to subject the ends of the armature to vibratory movements between the pole pieces of the respective sets and corresponding to the sound to be transmitted. A winding or voice coil carried by a winding spool is electromagnetically coupled to the armature, whereby an electromotive force is generated in the winding corresponding to the vibratory movements of the armature with respect to the adjacent pole pieces of the two sets, in a known manner. In prior telephone transmitters of this type, the vibratory armature is pivotally mounted on brackets or the like carried by the field structure or by an external supporting member.

While armature mountings of this character are 1 reasonably satisfactory, they are expenslvejto manufacture and require delicate adjustments in order properly to align the armature with pole pieces of the field structure. 7

Accordingly, it is an object of the present in vention to provide a sound translating d'evice of the type described having embodied therein an improved winding spool and armature assembly in which the armature is pivotally mounted on the winding spool and requires no external support- Another object of the invention is to provide an improved winding spool and armature assembly which is of extremely simple and rugged construction, and which is compact and economical to manufacture.

In general, the objects as set forth above are attained in accordance with the present invention by providing an assembly of the character noted, comprising a longitudinally split winding spool, including two complementary sections of similar construction, each of the sections being provided with a body. The body of one of the sections has a longitudinally extending recess therein disposed adjacent the joint between the sections and an armature is arranged in the recess in the body of the one section. Also, means is provided for securing the armature to the body of the one section, whereby the arma ture is mounted for vibratory movements out of contact with the walls of the bodies of the sections. More particularly the armature is provided with two transversely extending lugs which are secured by resilient clips to the body of the one section of the winding spool. Furthermore, the armature is formed of magnetic stock, while the sections of the winding spool are formed oi insulating material.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization and method of operation, together with furthenobjects and advantages thereof, will best be understood by reference to the following specification taken in connection ture assembly embodying the present invention;

Fig. 3 is a sectional view of a complete assembly; Fig. 4 is a plan view, partly broken away, of the assembly shown in Fig. '3; and Fig. 5 is a perspective view' of a mounting clip embodied in the assembly.

Referring now more particularly to Fig. 1 of' the drawing, there is illustrated a sound translating device in the form of a telephone transmitter of the magnetic or sound powered type embodying a winding spool and armature assembly constructed in accordance with the present invention and comprising a field structure I ll and a winding spool and armature assembly II. The field structure l0 includes a permanentmagnet l2 and two field members l3 and I4 rigidly secured'to the opposite ends thereof, the field member l3 being secured to the north pole of the permanent magnet l2, and the field member I 4 being secured to the south pole of the permanent magnet l2. The field members l3 and It are each provided with two pole pieces magnet 12.

It, is and I1, ll. respectively, the pole'pieces It and i1 being arranged in spaced-apart relation adjacent each other and constituting a set. and thepolepieces l4 and llbeingu'rangedin a similar manner and constituting a set.

The assembly comprises a winding spool I8 provided with a body It, carrying two spacedapart winding retaining heads I9", and a winding 20 arranged about the body isbetween the retainingheads l2". An armature 2| is pivotally mountedon the winding spool i! in a manner more iully described subsequently and is supported by the winding spool i9 between the two sets of pole pieces, one end 2| of the armature 2| being disposed between the oppositely disposed pole faces of the set of adjacent pole pieces I! and I1 and the other end 2| of the armature .2! being disposed between the oppositely disposed pole faces of the set of adjacent pole pieces l4 and II. The armature 2| is arranged within a longitudinally extending opening provided in the winding spool i2, and the ends 2|- and 2|" thereof are adapted to vibrate pieces l5. l1 and I2, II respectively, vand out of contact with the wall of the body of the winding spool II. Inc end 2|- oi the armature 2| is provided with a projecting operating lug 22 hav-. ing an opening therein in which one end of a rod 22 is secured, the rod 22 extending through an opening I! formed in thefield member I2, and the other end thereof being secured to a sound wave responsivediaphragm 24 supported about its periphery by suitable clamping means 2!. Normally, the armature 2| occupies a position wherein the opposite ends thereof are disposed intermediate the ad'jacent pole pieces 01' the two sets and is adapted to be vibrated by the rod 22 when the diaphragm 24 is vibrated by sound. waves impinging thereon. Thus, the movement of the armature 2| is controlled in accordance with the vibratory movements of the diaphragm 24, the vibratory movements of the diaphragm 24 corresponding to the vibrations of the air produced by the sound to be transmitted.

of fiat magnetic stock. The winding spool 40 is 4 split longitudinally and comprises two complebetween the associated sets of adjacent pole mentary upper and lower sections 40- and 40. respectively, of similar construction. Each of the sections includes a body 42 carrying two spacedapart winding retaining heads 43. The wall of the body 42 of the lower section 4i) is provided with a longitudinally extending recess 42 therein, which is disposed adjacent the joint between the upper and lower sections 40 and 40", respectively. The wall of the body'oi the upper section 40* is substantially flat adjacent the joint between the upper and lower sections 42* and 40", respectively. The armature 4| is provided with a longitudinally extending operating lug 4| and two transversely extending spacedapart lugs 41 intermediate the ends thereof. Each of the lugs 41 projects from one side of the armature 4| and is provided with a head 41- connected by a length 41 to the armature 4|, the length 41' being of reduced cross-sectional area. The armature 4| is arranged in a recess 42' provided in the wall of the body 42 of the lower section 40', the armature 4| being retained in position by spaced-apart and aligned recesses 42' in the lower section 40 and receiving the heads 41" on the lugs 41. The lugs 41 are retained in the recesses 42 provided in the body 42 of the lower section 40 by two mounting clips 42. As best shown in Fig. 5, each of the clips 48 is of substantially U-shape, comprising two flanges 42 and BI, the flange 50 being provided with threespaced-apart fingers 5|, I2 and I52. Each of the clips 48 embraces one side of the body 42 of the lower section 40", the clip 42 being retained in place by the clamping action between the two outside fingers II and 53 and the flange 42 upon the body 42. The intermediate finger 52 on the clip 48 engages the head 41 on one of the lugs 41', thereby rigidly securing the lug to the body 42 oi the lower section 40*. The clips in mount the armature 4| on the body 42 of the lower section 4|!" for vibratory movements about an axis extending As the armature 2| is moved in a clockwise from the north pole of the permanent magnet II by way of the field member It, the pole piece ll,

the armature 2|, the pole piece l1, and the field member l4 to the south pole of the permanent magnet l2. On the other hand, when the armature is moved in a counterclockwise direction about its pivot, the magnetic field of the field structure ll traverses a path extending from the northpole oi the permanent magnet l2 by way of the field member l2, the pole piece II, the armature 2|, the pole piece I2, and the field member H to the south pole of the permanent 'I'hils, during the vibratory movements of the armature 2|, the magnetic field of the field structure I2 traverses the armature 2| in opposite directions, causing a correspon in! electromotive force to be generated in the winding 22 electromagnetically coupled thereto. The

electromotive force generated in the winding 22 is transmitted to adistant point where it is utilisedinasuitablereceiverorotherttans such-as Bakelite and an armature 4| formed between the lugs 41 transversely of the winding spool 40.

In constructing the assembly NB the armsture 4| is brought into position with respect to the recess 42 provided in the body 42 or the pro-formed lower section 40 0! the winding spool 42 and lowered .into place, the heads 41' on the lugs 41 being received in the recesses 42 formed in the body 42. The clips 48 are then placed upon thesides oi the body 42 and the outside fingers II and II and the flange 48 are bent into engagement with the body 42 in order securely to fasten the clips 48 thereto. The armature 4| is then aligned and the intermediate fingers 42 are then bent into engagement with the heads 41' on the lugs 41, in order securely to retain the armature 4| in position. The preformed upper section 4|! is then brought into superimposed relation with the lower section 44 to complete the assembly In, the upper and lower sections 44- and 40'', respectively, being retained together by the field structure of the telephone transmitter in"any suitable manner.

armature ll by the flanges 50 on the clips 48, the wall of the body of the upper section 40 being recessed only partially to receive the flanges 50 on the clips 48. Thus, the composite body of the assembled upper and lower sections 40 and 40", respectively, of the winding spool 40 is hollow, the walls of the individual bodies 42 of the upper and lower sections constituting a wall surrounding a narrow opening extending longitudinally therethrough; and the armature 6i is proportional to the force exerted upon the operating lug 4| over a wide range. Alsothe mounting clips 48 retain the armature in place 'on the lower section 40' of the winding spool 40 in a very satisfactory manner, as these clips being resilient compensatefor any expansion or contraction of the winding spool due to temperature changes or aging. Furthermore, these clips are not included in a metallic circuit, thereby' eliminating eddy current losses.

From the foregoing description it is apparent that a unitary winding spool and armature assembly for a telephone transmitter is provided, which is of rugged construction and comprises a minimum number of parts. Moreover, the assembly is compact and the pivotally mounted armature therein requires no external support. V'Jhile the features of the present invention have been illustrated as being embodied in a telephone transmitter, it is apparent thatthey may be readily embodied in a telephone receiver or other sound translating device,

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is contemplated to cover in the appended claims all such modifications as fall within the true spirit and scope of the present invention.

What is claimed is:

1. An assembly for a sound translating device comprising, in combination, a longitudinally split winding spool including two complementary sections of similar construction, each of said sections being provided with a body, an armature provided with two spaced-apart transversely extending lugs, and means including a clip for securing each of said lugs to the body of one of said sections, whereby said armature is mounted for vibratory movements about an axis extending transversely of said winding spool and out of contact with the bodies of said sections andsaid lugs are subjected to torsional strains when said armature is moved, each of said clips being of substantially U-shape comprising. two flanges one of which is provided with three spaced-apart fingers, the two outside fingers and the other flange of said clip being arranged to clamp the body of said one section therebetween, and the intermediate finger of said clip being arranged to clamp one of said lugs to the bodyof said one section.

2. An assembly for a sound translating device comprising, in combination, a longitudinally split winding spool including two complementary sections of similar construction, a continuous longitudinally extending winding surrounding said sections, said sections being so constructed and arranged that there is provided adjacent the joint therebetween an opening extending longitudinally through said winding spool, and a flat plate-like armature arranged between said sections in the opening extending through said winding spool and provided with lugsextending transversely of the longitudinal axis of said winding spool and substantially in the plane of said armature, said lugs being supported entirely between said sections and entirely within said winding, whereby said armature is mounted for vibratory movements about an axis extending between said lugs transversely of the longitudinal axis of said winding spool and out of contact with said sections.

3. An assembly for a sound translating device comprising, in combination, a longitudinally split winding spool including two complementary sections of similar construction, a continuous longitudinally extending winding surrounding said sections, said sections being so constructed and arranged that there is provided. adjacent the joint therebetween an opening extending longitudinally through said winding spool, a flat platewithin said winding, whereby said armatureis.

mounted for vibratory movements about an axis extending between said lugs transversely of the longitudinal axis of said winding spool and out of contact with said sections.

4. An assembly for a sound translating device comprising, in combination, a longitudinally split winding spool including two complementary sections of similar construction, each of said sections being provided with a longitudinally extending body, a continuous longitudinally extending winding surrounding the bodies of said sections, the body of one of said sections having a longitudinally extending recess disposed therein adjacent the joint between said sections, a flat plate-like armature arranged in the recess in the body of said one section and provided with lugs extending transversely of the longitudinal axis of said winding spool and substantially in the plane of said armature, and means for securing said lugs to the body of said one section, whereby said armature is mounted entirely between said sections and entirely within said winding for vibratory movements about an axis extending between said lugs transversely of the longitudinal axis of said winding spool and out of contact with the bodies of said sections and said lugs are subjected to torsional strains when said armature is moved.

5. An assembly for a sound translating device comprising, in combination, a longitudinally split winding spool formed of insulating material and including two complementary sections of similar construction, a continuous longitudinally extending winding surrounding said sections, said sections being so constructed and arranged that there is provided adjacent the joint therebetween an opening extending longitudinally through said winding spool, a flat plate-like ranged between said sections in the opening extending through said winding spool. said armature being provided with integral lugs extending transversely of the longitudinal axis of said ing said lugs for supporting said lugs entirely armature formed of magnetic stock and ar-' between said sections and entirely within said winding, whereby said armature is mounted ior vibratory movements about an axis extending between said lugs transversely of the longitudinal axis of said winding spool and out of contact with said sections and said lugs are subjected to torsional strains when said armature is moved.

ALBERT E. WOODRUFF. 

